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Colorado School of Mines
1.
Marsico, Ryan M.
Implications of widespread dark production and decay of reactive oxygen species in natural waters.
Degree: PhD, Chemistry and Geochemistry, 2015, Colorado School of Mines
URL: http://hdl.handle.net/11124/20315 
► Light dependent and independent reactions produce and consume reactive oxygen species (ROS), including hydrogen peroxide (H2O2) and superoxide (O2-), in natural waters. ROS can act…
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▼ Light dependent and independent reactions produce and consume reactive oxygen species (ROS), including hydrogen peroxide (H2O2) and superoxide (O2-), in natural waters. ROS can act as oxidants or reductants to biologically important metals such as Fe, Cu, and Mn influencing their bioavailability. ROS produced in natural waters have also been linked to global phenomena such as harmful algal bloom fish kills and coral bleaching. In this thesis, we focus on the light independent (dark) reactions of ROS that are produced and decomposed by particle-associated processes, most likely microorganisms. However, before microorganisms can be implicated in ROS reactions we need to understand where, why, and how microorganisms as well as abiotic processes produce and decompose ROS. Ecological and geochemical stress factors that trigger ROS production and decomposition in natural waters are largely unknown. Therefore, we set out to measure the temporal and spatial variability of dark H2O2 production rates (PH2O2) and dark decay rate coefficients (kloss,H2O2) in freshwaters with a range of trophic states. Production rates were found to be comparable to production by photochemical processes. Furthermore, kloss,H2O2 correlated well with biological indicators (chlorophyll and cell counts) while PH2O2 did not. This suggests that while microorganisms are a common sink of H2O2, dark production may vary with microbial composition. We suspect that both a lake’s trophic state and the specific microbial consortia present in the system, at a given time, lead to the observed variability of ROS production in freshwater. The method for measuring dark PH2O2 in project one, which utilized an isotope tracer (H218O2), proved tedious, costly, and time consuming. Therefore, we used Amplex Red (AR) oxidation by H2O2 in the presence of horseradish peroxidase (HRP) catalyst as an effective alternative. We show that AR/HRP is suitable for measuring dark PH2O2 in freshwater by examining possible false positive and negative interferences, and methods to eliminate them. Catalase and HRP-free controls helped validate the AR method and revealed dark PH2O2 values of comparable magnitude and natural variability as previous studies. The dark redox cycling of mercury (Hg), especially the production of Hg(II), can lead to the formation of toxic methylated Hg compounds. Because dark reactions of Hg are largely an enigma and ROS are known to affect the redox cycling of metals in the ocean (e.g. Cu and Mn), we set out to understand if O2- plays a role in the dark biogeochemical cycle of Hg. Here, we measured O2- oxidation and reduction of Hg in filtered coastal (Vineyard Sound) seawater. O2- appeared to indirectly oxidize Hg0 in two seawater samples and O2- reduced Hg(II) in one seawater sample. We did not observe evidence of oxidation or reduction of Hg via secondary O2- reactions involving Mn, Cu, and nicotinamide adenine dinucleotide (NADH). However, our samples were filtered, and the proximity of NADH to cell surfaces may reveal a potential biological mechanism…
Advisors/Committee Members: Voelker, Bettina M. (advisor), Ranville, James F. (committee member), Cohen, Ronald R. H. (committee member), Spear, John R. (committee member), Hansel, Colleen (committee member).
Subjects/Keywords: dark production; natural waters; superoxide; hydrogen peroxide; dark decay; reactive oxygen species
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APA (6th Edition):
Marsico, R. M. (2015). Implications of widespread dark production and decay of reactive oxygen species in natural waters. (Doctoral Dissertation). Colorado School of Mines. Retrieved from http://hdl.handle.net/11124/20315
Chicago Manual of Style (16th Edition):
Marsico, Ryan M. “Implications of widespread dark production and decay of reactive oxygen species in natural waters.” 2015. Doctoral Dissertation, Colorado School of Mines. Accessed December 10, 2019.
http://hdl.handle.net/11124/20315.
MLA Handbook (7th Edition):
Marsico, Ryan M. “Implications of widespread dark production and decay of reactive oxygen species in natural waters.” 2015. Web. 10 Dec 2019.
Vancouver:
Marsico RM. Implications of widespread dark production and decay of reactive oxygen species in natural waters. [Internet] [Doctoral dissertation]. Colorado School of Mines; 2015. [cited 2019 Dec 10].
Available from: http://hdl.handle.net/11124/20315.
Council of Science Editors:
Marsico RM. Implications of widespread dark production and decay of reactive oxygen species in natural waters. [Doctoral Dissertation]. Colorado School of Mines; 2015. Available from: http://hdl.handle.net/11124/20315
Colorado School of Mines
2.
Schneider, Robin J.
Kinetics of biological hydrogen peroxide production.
Degree: PhD, Chemistry and Geochemistry, 2015, Colorado School of Mines
URL: http://hdl.handle.net/11124/20146
► Reactive oxygen species (ROS) such as hydrogen peroxide (H2O2), superoxide (O2-), and hydroxyl radical (HO•) are important to the biogeochemical cycling of trace metals and…
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▼ Reactive oxygen species (ROS) such as hydrogen peroxide (H2O2), superoxide (O2-), and hydroxyl radical (HO•) are important to the biogeochemical cycling of trace metals and carbon and could potentially have significant effects on marine processes. This study includes projects that examine both biological production and decay rates of H2O2 (and, to a lesser extent, O2-) at both the macroscopic (ecosystem) and microscopic (cellular) level. Dark production rates (PH2O2) and decay rate coefficients (kloss,H2O2) were determined by spiked batch incubations in the Prochlorococcus-dominated waters of Station ALOHA. Both parameters were low but exhibited considerable day-to-day variability, ranging from 0.0 to 2.9 nM hr-1 for PH2O2 and from 0.010 to 0.048 hr-1 for kloss,H2O2. A strong correlation was found between PH2O2 and kloss,H2O2 in the mixed layer. Concentration of biota yielded higher values for PH2O2 (4.5 to 8.4 nM hr-1) and enrichment incubations increased values of kloss,H2O2 (0.199 to 0.293 hr-1). Overall, biological production of H2O2 was expected to be significant compared to photochemical production. Production rates for both H2O2 and O2- of five species of marine diatoms were measured side by side by loading cells onto filters and using chemiluminescence detection of the ROS. In addition, the ability of these organisms to break down these ROS was examined by measuring recovery of O2- and H2O2 added to the analytical medium. O2- production rates ranged from zero to 7.3 x 10-16 mol cell-1 hr 1, while H2O2 production rates ranged from zero to 3.4 x 10-16 mol cell-1 hr-1. Results suggest that extracellular ROS production occurs through a variety of mechanisms even amongst similar organisms. In all organisms, recovery rates for killed cultures (94-100% H2O2; 10-80% O2-) were consistently higher than those for live cultures (65-95% H2O; 10-50% O2-). While recovery rates for killed cultures in H2O2 indicate that nearly all H2O2 is degraded by active cell processes, O2- decay appears to occur via a combination of active and passive processes. Overall, rates and pathways for ROS production and decay were shown to vary greatly from species to species, even among those that are closely related. Finally, twelve species of bacteria were evaluated for H2O2 production and decay both by the filter-loading method used for bacteria as well as the spiked batch incubation method used at Station ALOHA. Cell-normalized production rates (PH2O2,cell) ranged from zero to 3.81 amol cell-1 hr-1 and cell-density normalized decay rates (kH2O2,cell) ranged from 2.18 to 212 x 10-8 hr-1 (cell mL-1)-1. Values for kH2O2,cell and PH2O2,cell from the two methods generally agreed with each other, but in a few organisms there was a significant difference that indicated that H2O2 production might vary depending on an organism’s surroundings. Comparison of PH2O2,cell with previously published O2- production rates suggests that, as with diatoms, a variety of pathways are likely to be responsible for H2O2 production. Rates for kH2O2,cell and…
Advisors/Committee Members: Voelker, Bettina M. (advisor), Humphrey, John D. (committee member), Cohen, Ronald R. H. (committee member), Posewitz, Matthew C. (committee member), Hansel, Colleen (committee member).
Subjects/Keywords: diatoms; oceanography; bacteria; reactive oxygen species; hydrogen peroxide
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APA (6th Edition):
Schneider, R. J. (2015). Kinetics of biological hydrogen peroxide production. (Doctoral Dissertation). Colorado School of Mines. Retrieved from http://hdl.handle.net/11124/20146
Chicago Manual of Style (16th Edition):
Schneider, Robin J. “Kinetics of biological hydrogen peroxide production.” 2015. Doctoral Dissertation, Colorado School of Mines. Accessed December 10, 2019.
http://hdl.handle.net/11124/20146.
MLA Handbook (7th Edition):
Schneider, Robin J. “Kinetics of biological hydrogen peroxide production.” 2015. Web. 10 Dec 2019.
Vancouver:
Schneider RJ. Kinetics of biological hydrogen peroxide production. [Internet] [Doctoral dissertation]. Colorado School of Mines; 2015. [cited 2019 Dec 10].
Available from: http://hdl.handle.net/11124/20146.
Council of Science Editors:
Schneider RJ. Kinetics of biological hydrogen peroxide production. [Doctoral Dissertation]. Colorado School of Mines; 2015. Available from: http://hdl.handle.net/11124/20146
Colorado School of Mines
3.
Bandy-Baldwin, Kimberly M.
Investigation of groundwater-surface water interactions at selected sites along the Rio Grande using high frequency pressure observations.
Degree: MS(M.S.), Geology and Geological Engineering, 2007, Colorado School of Mines
URL: http://hdl.handle.net/11124/76833
► In the semi-arid southwestern United States, understanding the relationship between groundwater and surface water is important for sustainable water resources management. Albuquerque, NM, the largest…
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▼ In the semi-arid southwestern United States, understanding the relationship between groundwater and surface water is important for sustainable water resources management. Albuquerque, NM, the largest population center in the state of New Mexico, obtains water from the Santa Fe Aquifer Group and the Rio Grande; therefore interaction between these two connected water resources is particularly important for local legislators and regulators. The United States Geologic Survey (USGS) established the Middle Rio Grande Valley Monitoring Network to better quantify water resources in this area. High frequency pressure, high frequency temperature, geologic coring, and slug test data were collected at eight locations in the Albuquerque, NM area from 2003 to 2010. These data and the fully-integrated, physical hydrology model, ParFlow were used to model the Barelas cross-section in order to better understand the system's response to perturbations in river stage. Thirty-six ParFlow models were created assuming three different subsurface scenarios: homogenous, layered and correlated, Gaussian random field. The domain extent, spatial discretization, total run time, and topography were kept consistent between all scenarios. Seven hydraulic conductivity values and three specific storage values were tested. All ParFlow models were spun-up to ensure steady state conditions and simulated for the 2006-2007 water year. Model outputs were compared to corresponding physically observed values to determine goodness of model fit and to assess any trends in the data. Hydraulic conductivity and specific storage were shown to play very different roles in the model predictions.
Advisors/Committee Members: Maxwell, Reed M. (advisor), Benson, David A. (committee member), Cohen, Ronald R. H. (committee member).
Subjects/Keywords: NM; Albuquerque; groundwater-surface interactions; modeling; parameteric sensitivity; ParFlow; Rio Grande; Groundwater – New Mexico – Testing; Water quality – New Mexico – Testing; Stream measurements – New Mexico; Rio Grande (Colo.-Mexico and Tex.)
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APA (6th Edition):
Bandy-Baldwin, K. M. (2007). Investigation of groundwater-surface water interactions at selected sites along the Rio Grande using high frequency pressure observations. (Masters Thesis). Colorado School of Mines. Retrieved from http://hdl.handle.net/11124/76833
Chicago Manual of Style (16th Edition):
Bandy-Baldwin, Kimberly M. “Investigation of groundwater-surface water interactions at selected sites along the Rio Grande using high frequency pressure observations.” 2007. Masters Thesis, Colorado School of Mines. Accessed December 10, 2019.
http://hdl.handle.net/11124/76833.
MLA Handbook (7th Edition):
Bandy-Baldwin, Kimberly M. “Investigation of groundwater-surface water interactions at selected sites along the Rio Grande using high frequency pressure observations.” 2007. Web. 10 Dec 2019.
Vancouver:
Bandy-Baldwin KM. Investigation of groundwater-surface water interactions at selected sites along the Rio Grande using high frequency pressure observations. [Internet] [Masters thesis]. Colorado School of Mines; 2007. [cited 2019 Dec 10].
Available from: http://hdl.handle.net/11124/76833.
Council of Science Editors:
Bandy-Baldwin KM. Investigation of groundwater-surface water interactions at selected sites along the Rio Grande using high frequency pressure observations. [Masters Thesis]. Colorado School of Mines; 2007. Available from: http://hdl.handle.net/11124/76833
Colorado School of Mines
4.
Yaffe, Bethany Grace Marie.
Analytical methods for characterizing oil and gas development and production waste streams : a critical review and collaborative inter-laboratory comparison.
Degree: MS(M.S.), Civil and Environmental Engineering, 2007, Colorado School of Mines
URL: http://hdl.handle.net/11124/465
► As the oil and gas industry expands in the United States, managing the high volume waste streams generated during development and production becomes increasingly crucial…
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▼ As the oil and gas industry expands in the United States, managing the high volume waste streams generated during development and production becomes increasingly crucial to the preservation of ecosystem and human health. Accurate characterization is essential to ensure proper treatment and disposal. Therefore, a collaborative inter-laboratory comparison was performed using methods applied to oil and gas development and production wastewaters. Four samples were analyzed using five different methods. The samples included raw fracturing flowback, treated fracturing flowback, raw produced water, and treated produced water. The methods used to characterize these waters were EPA Method 300.0, EPA Method 200.7, EPA Method 200.8, SW 846 Method 6010C, and SW 846 Method 8015B. The mean, standard deviation, and relative standard deviation of the results from this inter-laboratory comparison were compared to the mean, standard deviation, and relative standard deviation found in each of the EPA methods validation data. This comparison elucidated the variation resulting from the application of the EPA methods to the oil and gas development and production wastewater matrices.
Advisors/Committee Members: Cath, Tzahi Y. (advisor), Higgins, Christopher P. (committee member), Cohen, Ronald R. H. (committee member).
Subjects/Keywords: analytical methods; Produced water; Inter-laboratory comparison; Fracturing flowback water; Petroleum waste – Analysis; Petroleum industry and trade – Waste disposal; Petroleum industry and trade – Environmental aspects
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APA (6th Edition):
Yaffe, B. G. M. (2007). Analytical methods for characterizing oil and gas development and production waste streams : a critical review and collaborative inter-laboratory comparison. (Masters Thesis). Colorado School of Mines. Retrieved from http://hdl.handle.net/11124/465
Chicago Manual of Style (16th Edition):
Yaffe, Bethany Grace Marie. “Analytical methods for characterizing oil and gas development and production waste streams : a critical review and collaborative inter-laboratory comparison.” 2007. Masters Thesis, Colorado School of Mines. Accessed December 10, 2019.
http://hdl.handle.net/11124/465.
MLA Handbook (7th Edition):
Yaffe, Bethany Grace Marie. “Analytical methods for characterizing oil and gas development and production waste streams : a critical review and collaborative inter-laboratory comparison.” 2007. Web. 10 Dec 2019.
Vancouver:
Yaffe BGM. Analytical methods for characterizing oil and gas development and production waste streams : a critical review and collaborative inter-laboratory comparison. [Internet] [Masters thesis]. Colorado School of Mines; 2007. [cited 2019 Dec 10].
Available from: http://hdl.handle.net/11124/465.
Council of Science Editors:
Yaffe BGM. Analytical methods for characterizing oil and gas development and production waste streams : a critical review and collaborative inter-laboratory comparison. [Masters Thesis]. Colorado School of Mines; 2007. Available from: http://hdl.handle.net/11124/465
Colorado School of Mines
5.
Bray, Jared M.
Potential leachability of mine tailings encapsulated in structural concrete, The.
Degree: MS(M.S.), Civil and Environmental Engineering, 2007, Colorado School of Mines
URL: http://hdl.handle.net/11124/79435
► The mining and milling activities associated with extraction of metals directly generates waste in the form of mine tailings. This material is one of the…
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▼ The mining and milling activities associated with extraction of metals directly generates waste in the form of mine tailings. This material is one of the largest sources of heavy metal contamination via water, air, flora, and fauna in the world. The re-use of this waste as an input to a construction material such as concrete could lead to a preventive method of reducing the environmental impact. This method of encapsulation of heavy metals has been applied to paste backfill; however, the compressive strength requirements are much lower compared to the ASTM standards for structural concrete. The objectives of this study were: (a) to examine the feasibility of maintaining the structural integrity of concrete, with compressive strength of 4,000 psi or greater with a slump of 3-4 inches, when using mine tailings as a fine aggregate, (b) investigate the ability of this material to encapsulate heavy metals, sulfates, and acid. The waste material, collected from the Pride of the West mill in Silverton, CO, was first physically and chemically characterized. After performing batch leach extraction tests, the raw mine tailing leachate contained heavy metal concentrations above conservative regulatory limits. Then, the optimal tailing to fine aggregate ratio was investigated. It was found that the compressive strength was comparable to control samples made with aggregate and the concentration of heavy metals found in the leachate were consistently low when the ratio varied below 50%. Therefore, the ASTM standard for the minimum allowable fineness modulus was used to obtain in maximum amount of mine tailings allotted in the concrete mixture. To examine whether metals could be leached from the concrete-tails mix, three extraction fluids varying in pH were used to accelerate the weathering process. The metals of concern were shown to have been thoroughly encapsulated in the concrete matrix, with a 2-4 log encapsulation capacity when compared to the metals leached from the raw tailings. Finally, a strength development experiment was conducted to observed changes over time. It was found that the specimens that contained mine tailings maintained comparable compressive strengths as the controls cylinders, above the minimum compressive strength requirements for structural concrete.
Advisors/Committee Members: Cohen, Ronald R. H. (advisor), Kiousis, Panagiotis Demetrios, 1956- (committee member), Wayllace, Alexandra (committee member).
Subjects/Keywords: Leachability; Encapsulation; Concrete; Mine tailings; Solidification; Stabilization; Tailings (Metallurgy); Leachate; Reinforced concrete; Heavy metals; Aggregates (Building materials); Hazardous substances – Environmental aspects
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APA (6th Edition):
Bray, J. M. (2007). Potential leachability of mine tailings encapsulated in structural concrete, The. (Masters Thesis). Colorado School of Mines. Retrieved from http://hdl.handle.net/11124/79435
Chicago Manual of Style (16th Edition):
Bray, Jared M. “Potential leachability of mine tailings encapsulated in structural concrete, The.” 2007. Masters Thesis, Colorado School of Mines. Accessed December 10, 2019.
http://hdl.handle.net/11124/79435.
MLA Handbook (7th Edition):
Bray, Jared M. “Potential leachability of mine tailings encapsulated in structural concrete, The.” 2007. Web. 10 Dec 2019.
Vancouver:
Bray JM. Potential leachability of mine tailings encapsulated in structural concrete, The. [Internet] [Masters thesis]. Colorado School of Mines; 2007. [cited 2019 Dec 10].
Available from: http://hdl.handle.net/11124/79435.
Council of Science Editors:
Bray JM. Potential leachability of mine tailings encapsulated in structural concrete, The. [Masters Thesis]. Colorado School of Mines; 2007. Available from: http://hdl.handle.net/11124/79435
Colorado School of Mines
6.
Hamilton, Ian.
Production of elemental sulfur and bentonite clay granules in a rotary drum.
Degree: MS(M.S.), Metallurgical and Materials Engineering, 2007, Colorado School of Mines
URL: http://hdl.handle.net/11124/78756
► Biological oxidation of sulfur granules is a critical component in elemental sulfur fertilizers since it converts sulfur to plant available sulfate. The level of biological…
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▼ Biological oxidation of sulfur granules is a critical component in elemental sulfur fertilizers since it converts sulfur to plant available sulfate. The level of biological oxidation is, in turn, regulated by the size and surface area of the sulfur granules. The aim of this research was to produce coarse sulfur granules that disintegrate to the correct particle size for biological oxidation, as well as the correct size for ballistic distribution from a spreader. Thus the interaction between mineral powders such as serpentine rock was investigated to get a better understanding of how these types of minerals react at different size fractions in granulation. Sulfur granules were developed from mixtures of 10% sodium bentonite clay with molten elemental sulfur. This was accomplished by sprayed a mixture bentonite and elemental sulfur into a falling curtain of fine material powder within a rotating drum. When comparing the seed materials, the serpentine rock showed sufficiently lower electrostatic build-up than phosphate rock. Serpentine rock also appears to help facilitate the disintegration of the granules when they are exposed to water. The outcome of the research was that it is possible to make a granulated sulfur fertilizer that had the correct size fraction and disintegration characteristics suitable for agronomic use.
Advisors/Committee Members: Ayers, Reed A. (advisor), Olson, D. L. (David LeRoy) (committee member), Cohen, Ronald R. H. (committee member).
Subjects/Keywords: Sulfur; Fertilizer; Bentonite; Bentonite; Fertilizers – Research; Sulfur fertilizers
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APA (6th Edition):
Hamilton, I. (2007). Production of elemental sulfur and bentonite clay granules in a rotary drum. (Masters Thesis). Colorado School of Mines. Retrieved from http://hdl.handle.net/11124/78756
Chicago Manual of Style (16th Edition):
Hamilton, Ian. “Production of elemental sulfur and bentonite clay granules in a rotary drum.” 2007. Masters Thesis, Colorado School of Mines. Accessed December 10, 2019.
http://hdl.handle.net/11124/78756.
MLA Handbook (7th Edition):
Hamilton, Ian. “Production of elemental sulfur and bentonite clay granules in a rotary drum.” 2007. Web. 10 Dec 2019.
Vancouver:
Hamilton I. Production of elemental sulfur and bentonite clay granules in a rotary drum. [Internet] [Masters thesis]. Colorado School of Mines; 2007. [cited 2019 Dec 10].
Available from: http://hdl.handle.net/11124/78756.
Council of Science Editors:
Hamilton I. Production of elemental sulfur and bentonite clay granules in a rotary drum. [Masters Thesis]. Colorado School of Mines; 2007. Available from: http://hdl.handle.net/11124/78756
Colorado School of Mines
7.
Coday, Bryan Douglas.
Engineered osmosis technology for desalination of oil and gas exploration wastewaters : assessment of membrane performance and process sustainability.
Degree: PhD, Civil and Environmental Engineering, 2007, Colorado School of Mines
URL: http://hdl.handle.net/11124/17122
► The United States is experiencing rapid growth in oil and gas (O&G) exploration and production. Consequently, there is an ever-increasing demand for water, necessary for…
(more)
▼ The United States is experiencing rapid growth in oil and gas (O&G) exploration and production. Consequently, there is an ever-increasing demand for water, necessary for well drilling and for enhancement of O&G extraction from different formations. At a single drilling location, over 1,000,000 gallons of drilling wastewater and 5,000,000 gallons of hydraulic fracturing wastewater can be generated in the course of several weeks. This wastewater contains chemicals that assist in drilling and hydraulic fracturing, minerals leached from subsurface formations, and dissolved and suspended organic and inorganic contamination. Ultimately, this water is permanently removed from the local fresh water cycle, as deep well injection is the current method of disposal; this disposal technique can be perceived as an environmental threat to local and regional groundwater supplies when conducted improperly. In order to be reused in further oil and gas exploration, and minimize the environmental impacts on local and regional water supplies, low cost treatment is necessary that is robust under harsh operating conditions and minimal field resources. An emerging membrane technology that can treat impaired water for industrial reuse is forward osmosis (FO). In FO, a highly concentrated draw solution imparts an osmotic pressure difference across a semipermeable membrane to extract water from impaired feed solutions. The use of FO has already shown many advantages in the treatment of a variety of complex industrial wastewaters. The main advantages include low hydraulic pressure operation, reduced fouling propensity compared to pressure-driven membrane processes, and high rejection of emerging contaminants and dissolved solids. While field and pilot-scale testing of FO at the industrial level have proved promising, there is still much to learn about the performance and sustainability of the FO process when treating O&G exploration and production wastewaters. Therefore, my dissertation investigated the benefits, performance, and sustainability of different configurations of the FO process for treatment of wastewater generated by the upstream sector of the O&G industry. These investigations included: (1) a comprehensive review of the principles and state-of-the-art of FO, and its successful development and demonstration in the upstream sector of the O&G industry, (2) an investigation of the changes in membrane performance as a function of increasing hydraulic TMP, which highlights the knowledge gap that still exists between standardized membrane comparisons at the bench-scale and performance comparisons under hydraulic conditions common in industrial applications, (3) an evaluation of the impacts of high ionic strength on membrane surface charge (zeta potential) using a combination of streaming potential measurements and theoretical modeling, (4) the impacts of membrane selection and operating conditions on the performance of FO membranes for treatment and desalination of raw produced water from shale gas operations, (5) an exploration of the…
Advisors/Committee Members: Cath, Tzahi Y. (advisor), Munakata Marr, Junko (committee member), Way, J. Douglas (committee member), Cohen, Ronald R. H. (committee member).
Subjects/Keywords: Engineered Osmosis; Industrial Wastewater; Hydraulic Fracturing; Forward Osmosis; Wastewater; Produced Water; Membranes (Technology); Osmosis; Oil field brines; Sewage – Purification; Saline water conversion; Hydraulic fracturing; Petroleum industry and trade – Water-supply
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APA (6th Edition):
Coday, B. D. (2007). Engineered osmosis technology for desalination of oil and gas exploration wastewaters : assessment of membrane performance and process sustainability. (Doctoral Dissertation). Colorado School of Mines. Retrieved from http://hdl.handle.net/11124/17122
Chicago Manual of Style (16th Edition):
Coday, Bryan Douglas. “Engineered osmosis technology for desalination of oil and gas exploration wastewaters : assessment of membrane performance and process sustainability.” 2007. Doctoral Dissertation, Colorado School of Mines. Accessed December 10, 2019.
http://hdl.handle.net/11124/17122.
MLA Handbook (7th Edition):
Coday, Bryan Douglas. “Engineered osmosis technology for desalination of oil and gas exploration wastewaters : assessment of membrane performance and process sustainability.” 2007. Web. 10 Dec 2019.
Vancouver:
Coday BD. Engineered osmosis technology for desalination of oil and gas exploration wastewaters : assessment of membrane performance and process sustainability. [Internet] [Doctoral dissertation]. Colorado School of Mines; 2007. [cited 2019 Dec 10].
Available from: http://hdl.handle.net/11124/17122.
Council of Science Editors:
Coday BD. Engineered osmosis technology for desalination of oil and gas exploration wastewaters : assessment of membrane performance and process sustainability. [Doctoral Dissertation]. Colorado School of Mines; 2007. Available from: http://hdl.handle.net/11124/17122
Colorado School of Mines
8.
Williams, John.
Building a better wind forecast: a stochastic forecast system using a fully-coupled hydrologic-atmospheric model.
Degree: PhD, Geology and Geological Engineering, 2007, Colorado School of Mines
URL: http://hdl.handle.net/11124/76832
► Wind power is rapidly gaining prominence as a major source of renewable energy. Harnessing this promising energy source is challenging because of the intermittent nature…
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▼ Wind power is rapidly gaining prominence as a major source of renewable energy. Harnessing this promising energy source is challenging because of the intermittent nature of wind and its propensity to change speed and direction over short time scales. Accurate forecasting tools are critical to support the integration of wind energy into power grids and to maximize its impact on renewable energy portfolios. A numerical weather prediction tool is limited by model errors arising from simplifications in the way it represents the physics of the natural system. Land surface - atmosphere feedbacks are strongly dependent on both atmospheric processes and hydrologic processes at and below the land surface. It has been shown in the literature that improving the physical representation of these feedbacks leads to better forecast results for precipitation distribution and wind speeds. Key to this physical representation is soil moisture distribution. By using PF.WRF, a fully-coupled hydrologic and atmospheric model incorporating the ParFlow hydrologic model in the the Weather Research and Forecasting atmospheric code, it is possible to dynamically simulate water movements in the subsurface generating more realistic soil moisture fields to interact directly with atmospheric processes. This work traces uncertainty propagation from subsurface hydraulic conductivity through soil moisture and latent heat flux and into the atmosphere to analyze its impact on wind speed, the extent of that impact in the presence of prevailing winds, and the length scales over which that impact is important. A data assimilation system using an implementation of the ensemble Kalman filter is developed and verified to reduce uncertainty in simulated wind speed by informing the forecast system with observed soil moisture values, demonstrating that even in a small model domain wind speed is sensitive to variation in soil moisture distribution.
Advisors/Committee Members: Maxwell, Reed M. (advisor), Cohen, Ronald R. H. (committee member), Delle Monache, Luca (committee member), Hering, Amanda S. (committee member), Lundquist, Julie K. (committee member).
Subjects/Keywords: Wind forecasting; Wind power – Forecasting; Stochastic analysis
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APA (6th Edition):
Williams, J. (2007). Building a better wind forecast: a stochastic forecast system using a fully-coupled hydrologic-atmospheric model. (Doctoral Dissertation). Colorado School of Mines. Retrieved from http://hdl.handle.net/11124/76832
Chicago Manual of Style (16th Edition):
Williams, John. “Building a better wind forecast: a stochastic forecast system using a fully-coupled hydrologic-atmospheric model.” 2007. Doctoral Dissertation, Colorado School of Mines. Accessed December 10, 2019.
http://hdl.handle.net/11124/76832.
MLA Handbook (7th Edition):
Williams, John. “Building a better wind forecast: a stochastic forecast system using a fully-coupled hydrologic-atmospheric model.” 2007. Web. 10 Dec 2019.
Vancouver:
Williams J. Building a better wind forecast: a stochastic forecast system using a fully-coupled hydrologic-atmospheric model. [Internet] [Doctoral dissertation]. Colorado School of Mines; 2007. [cited 2019 Dec 10].
Available from: http://hdl.handle.net/11124/76832.
Council of Science Editors:
Williams J. Building a better wind forecast: a stochastic forecast system using a fully-coupled hydrologic-atmospheric model. [Doctoral Dissertation]. Colorado School of Mines; 2007. Available from: http://hdl.handle.net/11124/76832
Colorado School of Mines
9.
Huggins, Richard G.
Modeling the activated sludge process with gravity clarification using mixed-integer nonlinear programming.
Degree: PhD, Civil and Environmental Engineering, 2007, Colorado School of Mines
URL: http://hdl.handle.net/11124/10613
► The activated sludge process (ASP) is widely used to remove organics and nutrients from domestic wastewater. Traditional ASP designs are based on a paradigm of…
(more)
▼ The activated sludge process (ASP) is widely used to remove organics and nutrients from domestic wastewater. Traditional ASP designs are based on a paradigm of strict regulation, cheap energy, and overdesign. Because of this regulation first paradigm, engineers rely heavily on experience based design approaches, empirical studies, and iterative methods to produce ASP designs that meet regulatory targets. This dissertation improves upon these typical design approaches by applying a rigorous mathematical methodology for reducing combined investment and operating costs associated with ASP designs. An explicit mathematical programming model, using the Activated Sludge Model 3 and the double exponential layered settling model, was used to find ASP designs that represent the lowest combined costs. The model was presented as a Mixed-Integer Nonlinear Programming (MINLP) problem with complementarity constraints and solved using a random-multi start method. Uncertain factors were varied singly, and as a group, allowing the model to draw probabilistic inference about the reliability of least-cost ASP designs. Multiple solutions to the problem were obtained that reduced costs compared to a typical design solution by up to 25%. Perturbation of optimization model parameters was used to identify important parameters contributing to cost variability in excess of 40%. Quantitative safety factors (QSFs) were calculated using sample-averaged approximation optimization that included the probabilistic nature of model parameters. Lastly, a robust-optimal ASP design was obtained using QSFs that reduced costs compared to a typical design by 18% and which represented a risk of performance degradation due to uncertainty of less than 5%. Synthesis of the activated sludge and settler models with MINLP produced the following improvements from typical designs: High numbers of solutions improved confidence that MINLP methods can be used to design and control ASPs more efficiently and at a lower cost. Uncertainty was decreased by identifying important parameters that significantly impact optimal ASP costs. QSFs were used to decide which unit processes and operations required overdesigned to account for parameter uncertainty. In addition, the inclusion of equilibrium conditions as complementarity constraints increased model credibility as compared to earlier ASP optimizations.
Advisors/Committee Members: Figueroa, Linda A. (advisor), Guerra, Andres (advisor), Spear, John R. (committee member), Munakata Marr, Junko (committee member), Eggert, Roderick G. (committee member), Cohen, Ronald R. H. (committee member).
Subjects/Keywords: Wastewater; Reliability; Activated Sludge; MINLP; Multistart; Optimization; Sewage – Purification – Activated sludge process – Mathematical models; Sewage – Purification – Activated sludge process – Cost of operation; Programming (Mathematics); Mathematical optimization
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APA (6th Edition):
Huggins, R. G. (2007). Modeling the activated sludge process with gravity clarification using mixed-integer nonlinear programming. (Doctoral Dissertation). Colorado School of Mines. Retrieved from http://hdl.handle.net/11124/10613
Chicago Manual of Style (16th Edition):
Huggins, Richard G. “Modeling the activated sludge process with gravity clarification using mixed-integer nonlinear programming.” 2007. Doctoral Dissertation, Colorado School of Mines. Accessed December 10, 2019.
http://hdl.handle.net/11124/10613.
MLA Handbook (7th Edition):
Huggins, Richard G. “Modeling the activated sludge process with gravity clarification using mixed-integer nonlinear programming.” 2007. Web. 10 Dec 2019.
Vancouver:
Huggins RG. Modeling the activated sludge process with gravity clarification using mixed-integer nonlinear programming. [Internet] [Doctoral dissertation]. Colorado School of Mines; 2007. [cited 2019 Dec 10].
Available from: http://hdl.handle.net/11124/10613.
Council of Science Editors:
Huggins RG. Modeling the activated sludge process with gravity clarification using mixed-integer nonlinear programming. [Doctoral Dissertation]. Colorado School of Mines; 2007. Available from: http://hdl.handle.net/11124/10613
Colorado School of Mines
10.
Meyerhoff, Steven B.
Understanding heterogeneity and data assimilation in karst groundwater surface water interactions: the role of geophysics and hydrologic models in a semi-confined aquifer.
Degree: PhD, Geology and Geological Engineering, 2007, Colorado School of Mines
URL: http://hdl.handle.net/11124/78509
► Groundwater and surface water historically have been treated as different entities. Due to this, planning and development of groundwater and surface water resources, both quantity…
(more)
▼ Groundwater and surface water historically have been treated as different entities. Due to this, planning and development of groundwater and surface water resources, both quantity and quality are often also treated separately. Recently, there has been work to characterize groundwater and surface water as a single system. Karstic systems are widely influenced by these interactions due to varying permeability, fracture geometry and porosity. Here, three different approaches are used to characterize groundwater surface water interactions in karstic environments. 1) A hydrologic model, ParFlow, is conditioned with known subsurface data to determine whether a reduction in subsurface uncertainty will enhance the prediction of surface water variables. A reduction in subsurface uncertainty resulted in substantial reductions in uncertainty in Hortonian runoff and less reductions in Dunne runoff. 2) Geophysical data is collected at a field site in O'leno State Park, Florida to visualize groundwater and surface water interactions in karstic environments. Significant changes in resistivity are seen through time at two locations. It is hypothesized that these changes are related to changing fluid source waters (e.g groundwater or surface water). 3). To confirm these observations an ensemble of synthetic forward models are simulated, inverted and compared directly with field observations and End-Member-Mixing-Analysis (EMMA). Field observations and synthetic models have comparable resistivity anomalies patterns and mixing fractions. This allows us to characterize and quantify subsurface mixing of groundwater and surface in karst environments. These three approaches (hydrologic models, field data and forward model experiments), (1) show the complexity and dynamics of groundwater and surface mixing in karstic environments in varying flow conditions, (2) showcase a novel geophysical technique to visualize groundwater and surface water interactions and (3) confirm hypothesis of flow and mixing in subsurface karst environments.
Advisors/Committee Members: Maxwell, Reed M. (advisor), Cohen, Ronald R. H. (committee member), Revil, André, 1970- (committee member), Graham, Wendy D. (committee member), McCray, John E. (committee member).
Subjects/Keywords: Geophysics; Numerical Modeling; Karst; Groundwater and Surface Water Interactions; Hydrology, Karst; Groundwater; Aquifers; Geophysics; Hydrologic models
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APA (6th Edition):
Meyerhoff, S. B. (2007). Understanding heterogeneity and data assimilation in karst groundwater surface water interactions: the role of geophysics and hydrologic models in a semi-confined aquifer. (Doctoral Dissertation). Colorado School of Mines. Retrieved from http://hdl.handle.net/11124/78509
Chicago Manual of Style (16th Edition):
Meyerhoff, Steven B. “Understanding heterogeneity and data assimilation in karst groundwater surface water interactions: the role of geophysics and hydrologic models in a semi-confined aquifer.” 2007. Doctoral Dissertation, Colorado School of Mines. Accessed December 10, 2019.
http://hdl.handle.net/11124/78509.
MLA Handbook (7th Edition):
Meyerhoff, Steven B. “Understanding heterogeneity and data assimilation in karst groundwater surface water interactions: the role of geophysics and hydrologic models in a semi-confined aquifer.” 2007. Web. 10 Dec 2019.
Vancouver:
Meyerhoff SB. Understanding heterogeneity and data assimilation in karst groundwater surface water interactions: the role of geophysics and hydrologic models in a semi-confined aquifer. [Internet] [Doctoral dissertation]. Colorado School of Mines; 2007. [cited 2019 Dec 10].
Available from: http://hdl.handle.net/11124/78509.
Council of Science Editors:
Meyerhoff SB. Understanding heterogeneity and data assimilation in karst groundwater surface water interactions: the role of geophysics and hydrologic models in a semi-confined aquifer. [Doctoral Dissertation]. Colorado School of Mines; 2007. Available from: http://hdl.handle.net/11124/78509
Colorado School of Mines
11.
Elliott, Lee Garrett.
Establishment and characterization of a bioenergy-focused microalgal culture collection using high-throughput methodologies, The.
Degree: PhD, Civil and Environmental Engineering, 2007, Colorado School of Mines
URL: http://hdl.handle.net/11124/23
► A promising renewable energy scenario involves utilizing microalgae as biological solar cells to capture the energy in sunlight and then harvesting the biomass for renewable…
(more)
▼ A promising renewable energy scenario involves utilizing microalgae as biological solar cells to capture the energy in sunlight and then harvesting the biomass for renewable energy production. Through photosynthesis photons are captured by light-sensitive pigment molecules and used to create a cellular chemical energy gradient. Microalgae ultimately use this energy gradient to drive their metabolism by reducing inorganic carbon into renewable, energy-rich organic hydrocarbon stores such as triacylglycerols (TAGs). These valuable molecules act as a cellular energy reserve, readily drawn from when required, often forming large oil-bodies within microalgal cells that can be abundant in certain oleaginous species. This is important for biofuel production because lipids can be extracted from biomass and then converted into a variety of biofuels such as renewable diesel and jet fuel. Thus, from a biofuels perspective, maximizing lipid productivity in selected microalgal feedstock strains is considered essential to the development of an economically viable algal biofuels industry. To achieve this, many current research and development efforts are directed towards genetically engineering well-characterized microalgae to optimize TAG production; however, this approach is a time-consuming, costly prospect and the number of well-characterized strains is relatively few, especially when compared to the number of known extant species. Alternatively, microalgal feedstock optimization could be more readily accomplished by taking advantage of the prodigious natural diversity of microalgae in the environment and identifying native strains of microalgae that, through natural selection, already possess key metabolic traits necessary for commercial feedstock development. Formulated on this premise, a collaborative project between the National Renewable Energy Laboratory (NREL) and the
Colorado School of
Mines (CSM) recently established and cryopreserved a clonal microalgal culture collection containing 360 unique strains with preliminary data regarding lipid accumulation and the growth potential of select isolates. The goal of this work has been to 1) perform a far more detailed characterization of the algal culture collection by developing high throughput screening procedures and tools for identifying fast-growing, oleaginous strains; and 2) gather further insight into the microalgal diversity found in the southwestern United States. Herein is described in detail the rationale, methods, results and conclusions of these efforts.
Advisors/Committee Members: Posewitz, Matthew C. (advisor), Spear, John R. (advisor), Cohen, Ronald R. H. (committee member), Dorgan, John R. (committee member), Darzins, Al (committee member), Donohoe, Bryon S. (committee member).
Subjects/Keywords: Lipids; Biofuels; Bioprospecting; Cryopreservation; FACS; Microalgae; Microalgae; Microalgae – Biotechnology; Microalgae – Cultures and culture media – Methodology; Biomass energy; Renewable energy sources
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APA (6th Edition):
Elliott, L. G. (2007). Establishment and characterization of a bioenergy-focused microalgal culture collection using high-throughput methodologies, The. (Doctoral Dissertation). Colorado School of Mines. Retrieved from http://hdl.handle.net/11124/23
Chicago Manual of Style (16th Edition):
Elliott, Lee Garrett. “Establishment and characterization of a bioenergy-focused microalgal culture collection using high-throughput methodologies, The.” 2007. Doctoral Dissertation, Colorado School of Mines. Accessed December 10, 2019.
http://hdl.handle.net/11124/23.
MLA Handbook (7th Edition):
Elliott, Lee Garrett. “Establishment and characterization of a bioenergy-focused microalgal culture collection using high-throughput methodologies, The.” 2007. Web. 10 Dec 2019.
Vancouver:
Elliott LG. Establishment and characterization of a bioenergy-focused microalgal culture collection using high-throughput methodologies, The. [Internet] [Doctoral dissertation]. Colorado School of Mines; 2007. [cited 2019 Dec 10].
Available from: http://hdl.handle.net/11124/23.
Council of Science Editors:
Elliott LG. Establishment and characterization of a bioenergy-focused microalgal culture collection using high-throughput methodologies, The. [Doctoral Dissertation]. Colorado School of Mines; 2007. Available from: http://hdl.handle.net/11124/23
Colorado School of Mines
12.
Villegas, Fernando.
Geomechanical evaluation of a mechanical undercutting system in block caving.
Degree: PhD, Mining Engineering, 2007, Colorado School of Mines
URL: http://hdl.handle.net/11124/10635
► This thesis proposes to use a mechanical system to perform the undercutting, similar to the longwall method used in coal mines. In order to evaluate…
(more)
▼ This thesis proposes to use a mechanical system to perform the undercutting, similar to the longwall method used in coal
mines. In order to evaluate the technical feasibility of this option, a geomechanical evaluation about the feasibility of the implementation of this alternative system in block caving was developed.
Advisors/Committee Members: Kuchta, Mark (advisor), Nakagawa, Masami (committee member), Cohen, Ronald R. H. (committee member), Grubb, John W. (committee member), Chitombo, Gideon (committee member).
Subjects/Keywords: Block Caving; Undercut; Mining exploitation; Geomechanical; Caving mining – Mathematical models; Mechanics; Risk assessment; Mining engineering; Mineral industries
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APA (6th Edition):
Villegas, F. (2007). Geomechanical evaluation of a mechanical undercutting system in block caving. (Doctoral Dissertation). Colorado School of Mines. Retrieved from http://hdl.handle.net/11124/10635
Chicago Manual of Style (16th Edition):
Villegas, Fernando. “Geomechanical evaluation of a mechanical undercutting system in block caving.” 2007. Doctoral Dissertation, Colorado School of Mines. Accessed December 10, 2019.
http://hdl.handle.net/11124/10635.
MLA Handbook (7th Edition):
Villegas, Fernando. “Geomechanical evaluation of a mechanical undercutting system in block caving.” 2007. Web. 10 Dec 2019.
Vancouver:
Villegas F. Geomechanical evaluation of a mechanical undercutting system in block caving. [Internet] [Doctoral dissertation]. Colorado School of Mines; 2007. [cited 2019 Dec 10].
Available from: http://hdl.handle.net/11124/10635.
Council of Science Editors:
Villegas F. Geomechanical evaluation of a mechanical undercutting system in block caving. [Doctoral Dissertation]. Colorado School of Mines; 2007. Available from: http://hdl.handle.net/11124/10635
Colorado School of Mines
13.
Irons, Trevor P.
Flexible automatically adaptive surface nuclear magnetic resonance modelling and inversion framework incorporating complex data and static dephasing dynamics, A.
Degree: PhD, Geophysics, 2007, Colorado School of Mines
URL: http://hdl.handle.net/11124/80052
► Surface nuclear magnetic resonance (sNMR) is the only geophysical technique that can directly and non-invasively detect the presence of subsurface liquid water. The method has…
(more)
▼ Surface nuclear magnetic resonance (sNMR) is the only geophysical technique that can directly and non-invasively detect the presence of subsurface liquid water. The method has established itself as valuable tool for hydrologists and groundwater managers owing to the fact that both porosity and hydraulic conductivity estimates can be made using this technique. Although sNMR has enormous potential, there are many challenges with the technique which hinder it's more widespread adoption. For these reasons sNMR has primarily been used as a 1D groundwater sounding tool, although there exist myriad other applications for a method directly sensitive to liquid water. Simultaneously inverting the entire complex dataset as well as the employment of arrays of separated transmitter and receiver coils and integration with other geophysical methods can help to overcome these limitations. This requires modelling algorithms that can accommodate a widely varying set of survey configurations and scenarios. I present the innovative use of sNMR applied to two geotechnical problems: volcanic landslide hazard characterization on Mt. Baker, Washington and the monitoring of internal erosion in earthen embankments. These applications necessitated the development of a general modelling framework capable of handling arbitrary positioned transmitter and receiver coils as well as 3D water distribution. The advantages of comprehensive (whole dataset) inversion of the entire sNMR record have been established for time-domain inversions. However, these inversions are memory intensive and struggle to fit the phase portion of the dataset-necessitating the regretful dismissal of this valuable information. I instead consider the sNMR inversion problem in the frequency-domain for the first time. There are several benefits: effectively lossless compression, and the ability to easily incorporate and solve for static dephasing dynamics caused by magnetic field inhomogeneities. This has allowed for the first practical sNMR inversion capable of fitting complex field data, resulting in improved imaging.
Advisors/Committee Members: Li, Yaoguo (advisor), Oden, Charles P. (committee member), Sava, Paul C. (committee member), Ganesh, Mahadevan (committee member), Cohen, Ronald R. H. (committee member).
Subjects/Keywords: NMR; Electromagnetics; Hydrology; Hazard Detection; Geotechnical Engineering; Inverse Theory; Nuclear magnetic resonance; Groundwater; Inversion (Geophysics); Geotechnical engineering; Mathematical models; Electromagnetism
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APA (6th Edition):
Irons, T. P. (2007). Flexible automatically adaptive surface nuclear magnetic resonance modelling and inversion framework incorporating complex data and static dephasing dynamics, A. (Doctoral Dissertation). Colorado School of Mines. Retrieved from http://hdl.handle.net/11124/80052
Chicago Manual of Style (16th Edition):
Irons, Trevor P. “Flexible automatically adaptive surface nuclear magnetic resonance modelling and inversion framework incorporating complex data and static dephasing dynamics, A.” 2007. Doctoral Dissertation, Colorado School of Mines. Accessed December 10, 2019.
http://hdl.handle.net/11124/80052.
MLA Handbook (7th Edition):
Irons, Trevor P. “Flexible automatically adaptive surface nuclear magnetic resonance modelling and inversion framework incorporating complex data and static dephasing dynamics, A.” 2007. Web. 10 Dec 2019.
Vancouver:
Irons TP. Flexible automatically adaptive surface nuclear magnetic resonance modelling and inversion framework incorporating complex data and static dephasing dynamics, A. [Internet] [Doctoral dissertation]. Colorado School of Mines; 2007. [cited 2019 Dec 10].
Available from: http://hdl.handle.net/11124/80052.
Council of Science Editors:
Irons TP. Flexible automatically adaptive surface nuclear magnetic resonance modelling and inversion framework incorporating complex data and static dephasing dynamics, A. [Doctoral Dissertation]. Colorado School of Mines; 2007. Available from: http://hdl.handle.net/11124/80052
Colorado School of Mines
14.
Conner, Kimberly D.
Pressure oxidation of enargite concentrates containing gold and silver.
Degree: PhD, Metallurgical and Materials Engineering, 2007, Colorado School of Mines
URL: http://hdl.handle.net/11124/286
► This project proposed a selective moderate temperature and pressure approach to the study of pressure oxidation leaching of enargite concentrates, which may be applied to…
(more)
▼ This project proposed a selective moderate temperature and pressure approach to the study of pressure oxidation leaching of enargite concentrates, which may be applied to copper sulfide orebodies and concentrates containing significant arsenic. Previous industrial methods have employed sulfuric acid-oxygen pressure leaching, alkaline sulfide leaching, and roasting. The approach includes evaluating the chemical reactions taking place and the effects of pressure, temperature, pH and redox potential on the fate of the minerals present in the concentrates. The main objective of this project was to develop and confirm an innovative, alternative approach to selectively upgrade enargite concentrates to recover the copper, gold and silver values while selectively leaching the arsenic. Enargite concentrate minerals were characterized before and after the experiments to determine any changes in mineralogy, composition and morphology. Optimized pressure oxidation resulted in arsenic extraction of up to 47%. Mineralogically, the leached residues showed higher pyrite content than the feed sample by 6.5-15 weight percent with a slight decrease in the enargite content. Further work with high purity enargite specimens under optimized conditions clearly showed the selective separation of arsenic to solution with retention of copper in the solid phase based on the experimental mass balances. Specifically, covellite is highlighted in the leach residue. This particle shows enargite mineralization on the outer edges of a covellite particle, which may be due to particle orientation or removal of the covellite outer product layer during sample preparation for MLA. However, more importantly, the image clearly shows that the covellite phase is occurring in conjunction and direct association with enargite, as was predicted by the thermodynamic Eh-pH analysis. Covellite appears to be a direct decomposition product of selective dissolution of arsenic from enargite. In summary, the propensity for moderate temperature selective pressure oxidation for separation of arsenic from enargite appears to be promising. Larger scale testing, mineralogical characterization and further optimization are suggested to confirm these results.
Advisors/Committee Members: Anderson, Corby G. (advisor), Cohen, Ronald R. H. (committee member), Queneau, Paul (committee member), Taylor, Patrick R. (committee member), Vidal, Edgar E. (committee member).
Subjects/Keywords: Pressure Oxidation; Enargite; Enargite; Oxidation; Leaching; Arsenic; Hydrometallurgy
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APA (6th Edition):
Conner, K. D. (2007). Pressure oxidation of enargite concentrates containing gold and silver. (Doctoral Dissertation). Colorado School of Mines. Retrieved from http://hdl.handle.net/11124/286
Chicago Manual of Style (16th Edition):
Conner, Kimberly D. “Pressure oxidation of enargite concentrates containing gold and silver.” 2007. Doctoral Dissertation, Colorado School of Mines. Accessed December 10, 2019.
http://hdl.handle.net/11124/286.
MLA Handbook (7th Edition):
Conner, Kimberly D. “Pressure oxidation of enargite concentrates containing gold and silver.” 2007. Web. 10 Dec 2019.
Vancouver:
Conner KD. Pressure oxidation of enargite concentrates containing gold and silver. [Internet] [Doctoral dissertation]. Colorado School of Mines; 2007. [cited 2019 Dec 10].
Available from: http://hdl.handle.net/11124/286.
Council of Science Editors:
Conner KD. Pressure oxidation of enargite concentrates containing gold and silver. [Doctoral Dissertation]. Colorado School of Mines; 2007. Available from: http://hdl.handle.net/11124/286
Colorado School of Mines
16.
Anderson, Eric D.
Aeromagnetic signature of the geology and mineral resources near the Pebble porphyry Cu-Au-Mo deposit, southwest Alaska.
Degree: PhD, Geology and Geological Engineering, 2007, Colorado School of Mines
URL: http://hdl.handle.net/11124/11
► Aeromagnetic data are used to better understand the geology and mineral resources near the Late Cretaceous Pebble porphyry Cu-Au-Mo deposit in southwestern Alaska. The reduced-to-pole…
(more)
▼ Aeromagnetic data are used to better understand the geology and mineral resources near the Late Cretaceous Pebble porphyry Cu-Au-Mo deposit in southwestern Alaska. The reduced-to-pole (RTP) transformation of regional-scale aeromagnetic data show that the Pebble deposit is within a cluster of magnetic anomaly highs. Similar to Pebble, the Iliamna, Kijik, and Neacola porphyry copper occurrences are in magnetic highs that trend northeast along the crustal-scale Lake Clark fault. A high-amplitude, short- to moderate-wavelength anomaly is centered over the Kemuk occurrence, an Alaska-type ultramafic complex. Similar anomalies are found west and north of Kemuk. A moderate-amplitude, moderate-wavelength magnetic low surrounded by a moderate-amplitude, short-wavelength magnetic high is associated with the gold-bearing Shotgun intrusive complex. The RTP transformation of the district-scale aeromagnetic data acquired over Pebble permits differentiation of a variety of Jurassic to Tertiary magmatic rock suites. Jura-Cretaceous basalt and gabbro units and Late Cretaceous biotite pyroxenite and granodiorite rocks produce magnetic highs. Tertiary basalt units also produce magnetic highs, but appear to be volumetrically minor. Eocene monzonite units have associated magnetic lows. The RTP data do not suggest a magnetite-rich hydrothermal system at the Pebble deposit. The 10 km upward continuation transformation of the regional-scale data shows a linear northeast trend of magnetic anomaly highs. These anomalies are spatially correlated with Late Cretaceous igneous rocks and in the Pebble district are centered over the granodiorite rocks genetically related to porphyry copper systems. The spacing of these anomalies is similar to patterns shown by the numerous porphyry copper deposits in northern Chile. These anomalies are interpreted to reflect a Late Cretaceous magmatic arc that is favorable for additional discoveries of Late Cretaceous porphyry copper systems in southwestern Alaska. Aeromagnetic data help to understand the three-dimensional distribution of plutonic rocks near the Pebble porphyry copper deposit. Magnetic susceptibility measurements show that rocks in the Pebble district are more magnetic than rocks of comparable compositions in the Pike Creek-Stuyahok Hills volcano-plutonic complex. The reduced-to-pole transformation of the aeromagnetic data demonstrates that the older rocks in the Pebble district produce strong magnetic anomaly highs. The tilt derivative transformation highlights a strong, northeast-trending structural grain attributed to Tertiary volcanic rocks. Multiscale edge detection maps near-surface magnetic sources that are mostly outward dipping and coalesce at depth in the Pebble district. The total horizontal gradient of the 10 km upward continued magnetic data map a circular, deep magnetic contact along which the porphyry deposits occur. Forward and inverse magnetic modeling show that the magnetic rocks in the Pebble district extend to depths greater than 9 km. The magnetic inversion is…
Advisors/Committee Members: Zhou, Wendy (advisor), Hitzman, Murray Walter (committee member), Monecke, Thomas (committee member), Nabighian, Misac N. (committee member), Cohen, Ronald R. H. (committee member).
Subjects/Keywords: Aeromagnetic data; Porphyry; Pebble; Alaska; Aeromagnetic prospecting – Alaska; Porphyry – Alaska; Geology – Alaska; Mines and mineral resources – Alaska; Magnetic anomalies – Alaska
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APA ·
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APA (6th Edition):
Anderson, E. D. (2007). Aeromagnetic signature of the geology and mineral resources near the Pebble porphyry Cu-Au-Mo deposit, southwest Alaska. (Doctoral Dissertation). Colorado School of Mines. Retrieved from http://hdl.handle.net/11124/11
Chicago Manual of Style (16th Edition):
Anderson, Eric D. “Aeromagnetic signature of the geology and mineral resources near the Pebble porphyry Cu-Au-Mo deposit, southwest Alaska.” 2007. Doctoral Dissertation, Colorado School of Mines. Accessed December 10, 2019.
http://hdl.handle.net/11124/11.
MLA Handbook (7th Edition):
Anderson, Eric D. “Aeromagnetic signature of the geology and mineral resources near the Pebble porphyry Cu-Au-Mo deposit, southwest Alaska.” 2007. Web. 10 Dec 2019.
Vancouver:
Anderson ED. Aeromagnetic signature of the geology and mineral resources near the Pebble porphyry Cu-Au-Mo deposit, southwest Alaska. [Internet] [Doctoral dissertation]. Colorado School of Mines; 2007. [cited 2019 Dec 10].
Available from: http://hdl.handle.net/11124/11.
Council of Science Editors:
Anderson ED. Aeromagnetic signature of the geology and mineral resources near the Pebble porphyry Cu-Au-Mo deposit, southwest Alaska. [Doctoral Dissertation]. Colorado School of Mines; 2007. Available from: http://hdl.handle.net/11124/11
. 
Open Access Theses and Dissertations